If you want to turn HDMI video into art, then you might be interested in my Pixel Wrangler project: https://github.com/osresearch/pixel-wrangler
@th Curious if you think the Pixel Wrangler could drive a Mac Portable active matrix display? I have a broken Mac Portable that might make a good donor to put a RaspPi to run MiniVMac on.
@paulrickards 640x480x1 fits in the PixelWrangler frame buffer, so probably? The only question is how many IO pins are on the blue connector and do they need level shifting.
@paulrickards the same Toshiba T7900 and T7778A were used in the Tandy 1400FD/HD laptop LCD, although I haven't found a pinout: https://www.lo-tech.co.uk/wiki/Tandy_1400FD_Video
@th Interesting: the DA15 video port on the back of the Mac Portable isn't a standard Mac video port-- it's a digital output that closely matches the pins to the LCD display.
@paulrickards it looks like the "VIDEO" IC is a custom Apple VLSI chip (VGT7737). Does your Mac Portable work well enough to flash something on the display so that the timings for CL1, CL2, FLM and BLANK can be measured?
@th Unfortunately no. There's some other issue that I've yet to reveal, even after recapping, cleaning, repairing traces, and two new "hybrid" power modules.
I'd need to get someone else with a working Portable to take some measurements.
@th Wait, I did find this! See starting on page 97.
http://cdn.preterhuman.net/texts/computing/apple_hardware_devnotes/Portable.pdf
@paulrickards amazing! those are all achievable goals with the Pixel Wrangler, with some minor support hardware to turn PWM into the contrast voltage.
@th Sweet! What's the best way to get started? Do you have any finished PIxel Wrangler boards for sale? Or would an UPduino be a good starting point?
@th I did find a pin out of the Mac Portable display.